Borrowings (Junior Subordinated Debentures) (Details) (Junior Subordinated Debt [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended			1 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 30, 2006 Camden Capital Trust A [Member]	Dec. 31, 2012 Camden Capital Trust A [Member]	Jun. 30, 2011 Camden Capital Trust A [Member]	Dec. 31, 2006 Union Bankshares Capital Trust I [Member]	Dec. 31, 2012 Union Bankshares Capital Trust I [Member]	Dec. 31, 2008 Union Bankshares Capital Trust I [Member]
Debt Instrument [Line Items]
Proceeds from issuance of trust preferred securities				$ 36,100
Debt instrument, interest rate						6.71%
Value of outstanding common shares of subsidiary owned by company					1,100			248
Debt instrument, interest rate terms							The interest rate of the trust preferred securities until April 7, 2011 was a blended rate equal to the sum of (1) the product of 50% times the average three-month LIBOR plus 1.42%, plus (2) the product of 50% times 6.4725%. The rate is now the average three-month LIBOR plus 1.42%.
Debt interest rate, additional rate over three month LIBOR					0.14%
Trust preferred securities assumed in acquisition									8,000
Aggregate amount of junior subordinated debt issued to subsidiary by acquired company, prior to acquisition							8,200
Interest expense on junior subordinated debentures	2,500	2,600	2,800
Value of trust preferred securities included in Tier I Capital	$ 43,000
Percentage of trust preferred securities included in Tier I Capital ratio	19.50%